It is known in the processing of ligno-cellulosic biomass to pretreat the biomass prior to hydrolysis or fermentation. This pre-treatment can be in the form of soaking the ligno-cellulosic biomass and separating the water soluble (C5) species in the liquid stream from the solids, and steam exploding the solid stream, or just steam exploding the ligno-cellulosic biomass stream.
Because the pre-treatments are aggressive, they create by-products such as acetic acid and furfural. A large amount of effort has been spent on trying to remove the acetic acid and/or furfural after pre-treatment as these chemicals inhibit and suppress further processing such as fermentation.
To date, no one has successfully managed to remove the acetic acid from a pre-treated stream of ligno-cellulosic biomass.